U.S. Pat. No. 4,318,818, Letton et al., issued Mar. 9, 1982, discloses heavy-duty liquid detergents containing enzymes, preferably proteases, and an enzyme-stabilizing system comprising calcium ion and a low molecular weight carboxylic acid or salt, preferably a formate. The compositions can contain various surfactants and optional detergent ingredients, including perfumes.
Pending U.S. patent application Ser. No. 537,321, Mao, filed Sept. 29, 1983, discloses light duty liquid detergents containing proteases and mild detergent surfactants.